Re: [PATCH v3 1/5] KVM: nVMX: generate non-true VMX MSRs based on true versions

From: David Matlack
Date: Wed Nov 30 2016 - 13:05:47 EST


On Wed, Nov 30, 2016 at 3:16 AM, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
> On 30/11/2016 03:14, David Matlack wrote:
>>
>> /* secondary cpu-based controls */
>> @@ -2868,36 +2865,32 @@ static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata)
>> *pdata = vmx_control_msr(
>> vmx->nested.nested_vmx_pinbased_ctls_low,
>> vmx->nested.nested_vmx_pinbased_ctls_high);
>> + if (msr_index == MSR_IA32_VMX_PINBASED_CTLS)
>> + *pdata |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
>
> Almost: PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR must be
> added to both the low and high parts. Likewise below.
> I guess you can use vmx_control_msr to generate it, too.

SGTM.

Although that would mean the true MSRs indicate a bit must-be-0 while
the non-true MSRs are indicating it must-be-1, which seems odd.